Back Suid-Atlantiese Anomalie Afrikaans الشذوذ المغناطيسي في جنوب المحيط الأطلسي Arabic Anomalia de l'Atlàntic Sud Catalan Südatlantische Anomalie German Anomalía del Atlántico Sur Spanish Hego Atlantikoko Anomalia Basque بیهنجاری جنوب اقیانوس اطلس Persian Etelä-Atlantin anomalia Finnish Anomalie magnétique de l'Atlantique sud French Anomali Atlantik Selatan ID
26°37′S 49°04′W / 26.61°S 49.06°W
The South Atlantic Anomaly (SAA) is an area where Earth's inner Van Allen radiation belt comes closest to Earth's surface, dipping down to an altitude of 200 kilometres (120 mi). This leads to an increased flux of energetic particles in this region and exposes orbiting satellites (including the ISS) to higher-than-usual levels of ionizing radiation.
The effect is caused by the non-concentricity of Earth and its magnetic dipole and has been observed to be increasing in intensity recently.[quantify] The SAA is the near-Earth region where Earth's magnetic field is weakest relative to an idealized Earth-centered dipole field.